1. Field of the Invention
The present invention concerns a universally applicable apparatus for dynamically balancing all known ceiling fans. Known ceiling fans may be described as having one of two configurations of drive motor arrangements: "spinner" and "flywheel".
According to the known spinner motor arrangement, the rotor of an alternating current (AC) electric motor is held stationary with respect to the ceiling, whereas the stator of the AC motor supports and turns with the fan blades. According to the known flywheel motor arrangement, the stator of an AC motor is held stationary with respect to the ceiling, whereas the rotor of the AC motor turns a flywheel which supports and turns the fan blades.
Generally, the mass of the stator (spinner motor arrangement) or the flywheel (flywheel motor arrangement) is exploited in an attempt to resist the tendency of the known ceiling fans to "wobble". Specifically, bearing sets between the rotors and stators facilitate relative rotation whereas the tendency of the rotating body to move laterally as a consequence of rotational imbalance is resisted by the mass of the rotating body.
It is important to minimize wobble for both aesthetic and functional reasons. From an aesthetic perspective, it is both audibly and visually distracting when a ceiling fan wobbles. From a functional perspective, wobble is dangerous. In particular, wobble causes vibration which reduces the service life of the bearing sets, loosens electrical and mechanical connections, and substantially increases the potential of structural failure of the ceiling fan mounting system.
Wobble also induces undesirable cyclical stress in the blade holders which extend between the fan blades and the rotating body. Eventually, this cyclical stress will result in fracture of the blade holders. This is particularly the case when the blade holders are improperly constructed (e.g. fabricated from unauthorized recycled materials, improper casting temperature, excessive pitch, etc.).
2. Description of Related Art
It is known in the prior art to construct the flywheel out of rubber which enables the fan blades in a flywheel motor arrangement ceiling fan to move up and down thereby minimizing imbalance of the rotating body. A disadvantage of rubber flywheel construction is the tendency to structurally fail after a period of use.
A "balancing kit" is also known in the prior art. The balancing kit consists of a testing clip and a number of self-adhesive weights. Essentially, a ceiling fan is balanced by a trial-and-error procedure wherein the testing clip is temporarily fixed along the length of a stationary fan blade. When the proper location for the weight(s) is finally determined with the testing clip, the weight(s) are adhered to the fan blade. Disadvantages of the balance kit include the extensive time necessary to determine the proper location for the weight(s), the potential of the adhesive to deteriorate and the weight(s) to be centrifugally thrown from the rotating ceiling fan, statically balancing a dynamic device, and the unsightly appearance of the weight(s) on a fan blade.